246 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 12 



FAUCHEA Montagne, 1846 



Thallus solid, compressed or flat, rather regularly dichotomously 

 branched ; medulla of large cells without accompanying rhizoids, cortex 

 with more or less evident anticlinal filamentous rows of cells ; tetraspo- 

 rangia in irregular, somewhat nemathecioid sori on the thallus surface; 

 cystocarps within a swollen pericarp with or without hornlike projec- 

 tions ; the carpospores arising from a basal reticulate placenta. 



KEY TO SPECIES 



1. Plant erect and dichotomously branched .... F. galapagensis 

 1. Plant repent, flagelliferous, irregularly branched . F. rhizophylla 

 1. Plant involved, irregularly branched and curled . . . F. crispa 



Fauchea galapagensis n. sp.^^^ 

 Plate 82, Figs. 1, 2 



Plants to 10 cm tall (or more ?), the very short stipe 1 mm diam., 

 hardly enlarged to form the small holdfast, expanding immediately to the 

 cuneate base of the thin, gelatinous, dull rose-colored complanate blade ; 

 the thallus dividing 3-5 times irregularly dichotomously to form strap- 

 shaped nontapering segments to 1 cm wide below, 3 mm in the ultimate 

 branches; structurally with a medulla of large thin-walled colorless cells 

 in 1-3 layers, supporting an assimilative cortex of evident filaments in 

 loose branching anticlinal series, the cells of the inner part a little larger 

 and irregular in shape, these branching outwardly to oval cells which are 

 4-6 IX diam., all with thin walls and well spaced in the soft gelatinous 

 matrix; spermatangia developed from the surface cells, widely and evenly 

 distributed over considerable ill-defined areas; cystocarps crowded, mar- 

 ginal, projecting in a single series along the edges of the plant; carpo- 

 genic branches probably two (or three ?) celled, very small, immersed 

 in the cortex; cystocarps when partly matured showing a basal arachnoid 

 tissue of larger cells near the base of the spore mass, smaller and more 

 slender ones farther away, and this tissue at first filling the upper cavity 

 of the pericarp; gonimoblast mass arising from a large erect oval cell 

 which is directly connected with the basal tissue, most of the cells of the 

 gonimoblast being converted to spores, but a few large ones above the 



150 Fauchea galapagensis n. sp. — Plantae ad 10 cm altitudine, stipite brevis- 

 simo, lamina tenui, gelatinosa, abrupte expansa 3-5 irregulariter erecteque dicho- 

 tome furcata, segmentis infra ad 1 cm lat., supra 3 mm lat. ; cystocarpis confertis, 

 raarginalibus. Planta tvpica in loco dicto I. Santa Maria, Ecuador, legit W. R. 

 Taylor no. 34-375, 29 Jan. 1934. 



